DETAIL: Fiona Hyslop wants a business plan to be drawn up.
A study into the future of the commission, which was established in 1908, found that a merger with Historic Scotland offers the "greatest potential" for the future of the body.
Fiona Hyslop, the Scottish Government's cabinet secretary for culture and external affairs, is now seeking a business case in greater detail for the merger.
The report – commissioned by Scottish ministers – warned that the status quo for the body was "not desirable" and that the RCAHMS had suffered an "extended period of uncertainty" in recent years, with several attempts to merge it with Historic Scotland.
It added that although the "merger option is more financially sustainable and offers greater potential to deliver the primary benefits ... it would be a major change and so carries the highest risk".
Ms Hyslop said: "The functions of RCAHMS – to survey and analyse the built environment, as well as conserve its established collections – are vital in securing Scotland's built heritage for future generations.
"From the evidence presented in the options appraisal I believe a merger between RCAHMS and Historic Scotland could offer the best route to securing RCAHMS's important contribution to Scotland's culture.
"I have asked that a detailed business case is developed to explore the potential synergies between RCAHMS and Historic Scotland, and protects the staff and expertise of both organisations."
The commission has a current staff of around 115, all based in Edinburgh, and receives Scottish Government funding of £4million a year.
Diana Murray, secretary of the RCAHMS, said: "We welcome the publication of the report on the options appraisal and will make every effort to work with the Scottish Government and Historic Scotland on the development of a viable future for the role and functions of the RCAHMS within a new organisation."
RCAHMS was first established by Royal Warrant in 1908 to "make an inventory of the ancient and historical monuments and constructions connected with or illustrative of the contemporary culture, civilisation and conditions of life of the people of Scotland from the earliest times to the year 1707- and to specify those which seem most worthy of preservation".
Currently the organisation identifies, surveys and analyses the historic and built environment of Scotland.
It also preserves, cares for and adds to the information and items in its collections and promotes understanding, education and enjoyment through interpretation of the information it collects and the items it looks after.
RCAHMS has a duty defined in statute to record listed buildings and buildings in conservation areas for which permission to demolish or part-demolish has been granted under the Town and Country Planning (Scotland) Act 1997.
RCAHMS also provides information to the Ordnance Survey for updating antiquities depicted on its map series.